}
public void testNullPasswordLogin() throws Exception {
LoginContext context = new LoginContext(COMPLEX_REALM, new UsernamePasswordCallback(username, null));
context.login();
Subject subject = context.getSubject();
assertTrue("expected non-null subject", subject != null);
assertEquals("Principals", 0, subject.getPrincipals().size());
assertEquals("Private credentials", 0, subject.getPrivateCredentials().size());